When the news broke two weeks ago about a dramatic increase in thyroid cancer following the Fukushima nuclear disaster, I wasn’t skeptical. After all, thyroid cancer increased dramatically after Chernobyl, and this study appears in a reputable peerreviewed journal. However, after consulting with experts on all sides I was persuaded that the study is severely flawed and here’s why. While the study was based on an ongoing thyroid cancer screening campaign, it was not authored by the scientists conducting that campaign. The scientists conducting the screenings are from the Fukushima Medical University, and they do not agree.
With the results of this sensational study. It is likewise the consensus of the world’s leading experts that we are not yet observing an effective radiation in Fukushima. It’s also important to understand that the reported increase of cancer does not reflect an increase of patients seeking treatment. Instead, the best explanation is that screening campaigns increase the number of cancers that are detected by way of hunting for cancers at all stages of their development, including early stages were tiny cancers would not otherwise be detected. Prior to screening the only cancers that are detected are those that.
Have become large enough to produce symptoms that compel patients to seek treatment. So the resulting increase of cancer cases after screening is likely to produce an illusion of an epidemic if the number of prescreening cases is compared to the number of screening cases. Such an illusory epidemic is known as ‘detection bias’. To prevent detection bias the scientists at the Fukushima Medical University designed their study to exclude prescreening cases. And by their design the first few years after Fukushima, wherein no radiationcaused thyroid cancers are expected, will serve as the background data against which future.
Fukushima Thyroid Cancer
Cases will be compared. In this way, screening cases are compared to screening cases, thereby avoiding detection bias. However, the authors of the headlinegrabbing study shortcircuited that errorpreventing designed and used prescreening cases to compare to screening cases, which virtually guarantees that detection bias will skew the results toward an illusory epidemic. The headlinegrabbing study also ignores prior research predicting the magnitude of detection bias in the Fukushima screening campaign. And when we compare those predictions to the source data used in the headlinegrabbing study, we find that the prevalence of thyroid cancer discovered during the screening campaign falls.
Within the expected range of prevalence. So the only evidence of a thyroid epidemic presented by the headlinegrabbing study is merely an artifact of introducing detection bias coupled with failing to site prior research that predicted the same prevalence level that the headlinegrabbing authors would like us to believe is an epidemic. That being said, based on the Chernobyl experience it’s possible that we will see an increase in thyroid cancer within the next few years. And here’s another important fact indicating that we are not yet seeing any effects of radiation.
Perhaps the most important lesson of radiation research has been the dramatically elevated risk to children. This graph of radiation risk over the human lifespan shows the elevated risk to children. Risk of radiationinduced cancer decreases as we get older. This is Radiobiology 101. And here is the frequency of thyroid cancers by age at exposure to the Chernobyl nuclear disaster. The frequency of thyroid cancers was highest among those who were the youngest at the time of the accident. Exactly as a century of radiation research would predict. But here’s the.
Age distribution of thyroid cases after Fukushima, so far. There are literally no cases among the youngest ages of the thyroid screening population. And yet the youngest are expected to show the largest increase, if radiation is the cause. Consulting the Japanese Cancer Registry for the age distribution of thyroid cancer before Fukushima finds this age distribution, which matches the age distribution we see now after Fukushima. The obvious interpretation of these data are that we are not yet looking at a radiation impact on thyroid cancer in Fukushima. On the other hand, if we’re to accept the headlinegrabbing study and.
Believe that there is a radiation impact occurring at this time, then we should also want to rewrite the radiobiology textbooks, amending them to note that the youngest children are not the most atrisk demographic. But a simpler explanation is that there isn’t a radiation effect occurring right now, which is exactly what the scientists who are conducting the screening campaign believed to be the case. And they keep tally of this age distribution as a means of detecting if and when I radiogenic effect begins to occur. And I will do my best to track, vet and report that information as it comes.